Publications

Population levels of emperor geese (Chen canagica) in Alaska in 1993 were about half that estimated in the 1960s. Survival information is necessary for managers to decide how to best enhance recovery of this species to former levels. We calculated seasonal and annual estimates of emperor goose survival from resightings of neck-collared birds. Geese were neck collared in 1988-90 on their...

We examined coexistence at sea among 7 taxa of diving, wing-propelled seabirds (Alcidae) in the genera Aethia, Uria, Cepphus, and Fratercula. Species abundances were measured simultaneously with a suite of environmental factors in the northern Bering Sea, Alaska, USA; data from 260 adjacent and non-adjacent sites occupied by alcids foraging offshore near breeding colonies were then...

SUMMARY: A comparison is made of different methods of determining size of home range from grid trapping data. Studies of artificial populations show that a boundary strip method of measuring area and an adjusted range length give sizes closer to the true range than do minimum area or observed range length methods. In simulated trapping of artificial populations, the known range size

Sea ducks (tribe Mergini after Johnsgard 1960) are the most northerly distributed ducks, and species diversity is greatest in the North Pacific. They exploit a diversity of inshore and offshore marine habitats during the non-breeding season, and their use of habitat during breeding varies from coastal through freshwater wetlands of the tundra and taiga (Figure 1, Appendix 1). Non...

I quantified ovarian rapid follicle growth (RFG) and regression of postovulatory follicles of Northern Pintails (Anas acuta), American Wigeon (A. americana), and Lesser Scaup (Aythya affinis) by a method that accounted for within-day variation in follicle size. Objective methods for identifying onset of RFG also are presented; this is crucial for accurate classification of breeding...

Our objective was to determine if the occurrence and abundance of Pacific loons (Gavia pacifica Lawrence) and horned grebes (Podiceps auritus L.) on 123 wetlands of Yukon Flats National Wildlife Refuge in east central Alaska were related to the limnological characteristics of those wetlands. Aquatic bird-wetland use surveys were conducted in conjunction with limnological sampling from...

The number of spectacled eiders nesting on two study areas near the Kashunuk River, on the central Yukon-Kuskokwim (Y-K) Delta, Alaska, declined by over 75% in the last 20 years. Nesting densities have remained low, but have not significantly declined since 1985. There has been no decrease in the reproductive effort of individual females as indicated by average clutch sizes. There has...

The incidental catch of seabirds in high-seas drift nets was recorded in 1990-1991 by scientific observers on commercial squid and large-mesh fishery vessels operating in the North Pacific Transitional Zone. Twenty-six Synthliboramphus murrelet deaths were recorded in the months of August through December. All but one were from the Korean squid fishery in a small area bounded by 38°-44°N...

Accurate age-class determination of waterfowl is necessary for studies addressing age-specific effects (e.g., Serie et al., 1992) and age structure of populations (e.g., Raveling and Heitmeyer 1989). Duck ages can be determined in fall by morphological and color characteristics of tertial and tail feathers (Carney 1992); however, these feathers are replaced during fall and winter, thus...

The Exxron Valdez oil spill (EVOS) on 24 March 1989 threatened extensive areas of prime sea otter (Enhydra lutris) habitat along the coasts of south-central Alaska. The spill occurred in northeastern Prince William Sound (PWS), and oil moved rapidly south and west through PWS into the Gulf of Alaska. Much of the coastline of western PWS was heavily oiled, and the slick eventually spread...

Following the Exxon Valdez oil spill (EVOS), Prudhoe Bay crude oil from the vessel spread on the sea surface and covered coastal shores from western Prince William Sound (PWS) to the Alaska Peninsula. In PWS alone. acute mortality of sca otters at the time of the spill was estimated to be greater than 2000 (Doroff et al. 1993; Garrott et al. 1993). Shoreline oiling was observed on...

We studied morphological and mitochondrial DNA (mtDNA) divergence among three populations of Brachyramphus Murrelets: Kittlitz's Murrelets (B. brevirostris), and tree-nesting and ground-nesting Marbled Murrelets (B. marmoratus). We found little morphological divergence in external and skeletal measurements among Marbled Murrelets, but both populations were easily distinguished from...